Ridiculous... You can't have it both ways. You're contradicting yourself.
  1. Unprotected!! Your seed words are extremely secure
  2. Someone could have your seed already
You want to use a wallet with no passphrase to use as a "decoy" in case of $5 wrench attack? Feel free. If someone is actively targeting me, I doubt they're gonna believe I only have $100 worth of bitcoin. If they're NOT actively targeting me, why are they $5 wrench attacking me?? Sorry, I just don't buy it. You do you, I'm gonna use a passphrase. Good day